Proposal:

Generalized content markup (such as HTML) is complimented
by markup specifications that facilitate more semantically precise content
markup. Examples of specialized, semantically precise markup include MathML and MusicXML. Assistive technology (AT) typically handles generalized
content markup, but does not know about specialized markup. Because of
this, users of AT are unable to access or navigate specialized markup
effectively.

The Open A11y Expert
Handlers group is exploring a standardized plug-in mechanism for assistive
technology software. The goal of this plug-in standard is to allow AT to use expert
software plug-ins to provide access to specialized markup exposed through
accessibility APIs, such as MSAA and IAccessible2 on Windows and AT-SPI on Unix/Linux. This plug-in standard will allow AT to rely on expert
handler software to enable navigation and provide enhanced, semantically
rich access to specialized markup, enabling an AT to more properly render --
visually, aurally, and/or tactilely -- the semantic meaning encoded in
specialized markup, wherever such specialized markup is encountered: in
the context of a word processor document, a DAISY book, or a web page or
application.

The Open A11yExpert Handlers SIG has gathered
use cases and developed requirements for proposed plugin specifications
covering:

In this session, the panel will explain its work to date and invite
comments on its work from the audience. A comparison with existing
specialized markup assistive technology will be presented briefly as well
in order to illustrate the need for the platform and toolkit neutral
plugin mechanism Open A11y envisions.